Locomotive stoker



May 6, 1941. s. G. JONES LocoMoTIvE scpoxER Filed o-ct. 2, 19:59

2 Sheets-Sheet 1 :E: am: mul: ma: man een May 6, ll9, 4l." i s. G..loNEs 27,241,372

LOCOMOTIVE STOKER Filed Cct. 2, 1959 2 Sheets-Sheet 2 l 444 ATToRNEYs.

Patented May 6, 1941 2,241,372 LoooMo'rIvE sToKER.

Samuel G. Jones, Princess Anne County, Va., as-

signor to Berkley Machine Works and Foundry Company, Inc., Norfolk,

Virginia Va., a corporation of Application October 2, 1939, SerialNo.1297,428

8 Claims.

This invention relates to locomotive stokers, and more particularly tostokers of the type that deliver coal to the hre-box through an openingin its backwall.

In stokersof this character coal is fed forward by a conveyor screw froma trough beneaththe coal-bin on the locomotive tender and is movedupwardly through an inclined riser conduit to a jet member from whichjets of steam distribute the coal over the grate in the fire-box. Instokers which have a conveyor screw in the riser conduit more coal isdelivered to the jets at one side of the screw than to those at theother side. This is because the last ight of the screw in passingbeneath its hub pushes the coal to one side of the screw and then leavesit there as it passes over the hub back to the opposite side. That is,if the riser screw must be turned in a clockwise direction to convey'thecoal forward, more coal will be pushed toward the left side of thedelivery end of the riser conduit than to the right side. This meansthat the steam jets Will throw more coal toward the left side of thefire-box than toward the right. I-Ieretofore there has been no stokerthat is free of this trouble.

It is among the objects of this invention to provide a locomotive stokerwhich delivers coal to the jet member in substantially equal amounts onboth sides of the screw, and which does this by a simple and inexpensiveexpedient that does not complicate the stoker or increase its size.

In accordance with this invention a trough is mounted on a locomotivetender in a position to receive coal from its coal-bin, and'is connectedby a tubular conduit and a universal joint to the lower end of anupwardly and forwardly inclined riser conduit. To transfer coal from thetender to the fire-box, conveyor screws are rotatably mounted in thehorizontal and inclined conduits with their adjoining ends connectedtogether by universal joints. As the coal leaves the upper end of theriser conduit it passes over steam jets by which it is projected intothe firebox and distributed over the grate. The conveyor screw in theriser conduit has a normal conveyor thread encircling its hub for themajor portion of its length but terminating short of its upper end. Areverse thread is mounted on the hub between its upper end and the upperend of the conveyor thread and preferably extends only part way aroundthe hub. This reverse thread is so positioned relative to the conveyorthread that it removes some of the coal from the side of the hub towhich the conveyor thread de- (Cl. Htl-105.5)

livers the most coal and deposits it on the opposite side of the hub inorder to provide substantially equal amounts of coal at both sides ofthe screw. The upper portion of the riser conduit is enlarged, and thereverse flight, mounted on the tip portion of the screw hub, is buriedin the coal in its enlarged portion so that it will not pack coal in therestricted portion of the conduit and interfere with the operation ofthe Stoker. By tip portion is meant that portion of the screw hub whichis in the enlarged portion of the conduit and which projects above thenormal conveyor thread of the screw.

The preferred embodiment oi the invention is illustrated in theaccompanying drawings in which Fig. 1 is a side view of the front end ofmy locomotive stoker; Fig. 2 is a front view of the upper end of thestoker taken on the line II-II of Fig. 1; Fig. 3 is a rear view oi theriser conduit taken on the line III--III of Fig. 1; and Fig. 4 is an endview of the upper end of the riser screw.

Referring to Fig. 1 of the drawings, a conveyor trough (not shown) ismounted on the locomotive tender in the usual way below its coal-bin inorder to receive coal therefrom. Extending forwardly fromthe front ofthe trough to a point below the deck I of the locomotive cab is ahorizontal tubular conduit 2. The front end of the conduit is connectedby a suitable universal joint 3 to the lower end of an upwardly and Iforwardly inclined riser conduit 4 the upper end of which is mounted inrigid position relative to the backwall 6 of the locomotive boiler bybolting the riser to a bracket 1 on the locomotive frame beneath the cabdeck.

Coal is fed forward from the trough and through horizontal conduit 2 bymeans of a conveyor screw 8 that is driven from its rear end by anengine 9 mounted on the locomotive. The front end of this screw isconnected by means of a universal joint I I to the lower end of aconveyor screw I2 rotatably disposed in the riser conduit. As shown inFig. 3, the lower portion of the riser conduit is tubular, but the upperportion iiares out and is enlarged to substantially the width of thenormal hand-firing opening I3 above it. The rear wall of the enlargedportion of the riser is flat and is provided with an opening that isnormally elo-sed by a clean-out door I4 hinged at its bottom to theconduit and connected at its top to the conduit by bolts I6 pivotedthereto. As shown in Fig. 3, the cleanoutdoor is provided with a row ofopenings Il through which the fire-bed may be observed walls of theriser and project into depressions in the ends of the jet member (Fig.2).

AS Shown in Fig. 1, the rear wall of the jet member is inclined andforms a continuation of the adjoining portion of the riser licor, andits front wall is inclined downwardly and forwardly to an apron 24integral therewith that overlies the bottom of the backwall opening toprotect it fromV possible abrasion. The rear wall of the jet member isinclined downwardly from its center toward its ends as shown in Fig. ,2,so that the larger pieces of `coal which tend to` stay close to thescrew hub will roll toward the ends of the jet member and thereby give abetter distribution of coal. The lower portion of the jet member isprovided with passages connected by pipes 26 to a source of fluid underpressure, such as ,the steam in the locomotive boiler, and the inclinedfront wall of the jet member is provided witha plurality of jet orifices27 from which the steam issues for throwing coal upwardly and forwardly.The inside of the jet member is preferably divided by verticalpartitions 28 (Eig. 2) into four chambers yto `each of which steam isdelivered by a separate pipe 26 controlled by a manually operable valve29 so that the pressure in each chamber can he individually regulated toaid in giving control over fue distribution.,

y Coal which is thrown upwardly by the steam jets is intercepted anddeflected forwardly in all directions by a fuel-deiiecting member 3|.VThe deector is supported from its rear end by a substantially horizontalshaft 32 extending therethrough and pivotally mounted in lugs 334depending Afrom the top` wall o f the riser conduit. To prevent thisshaft from turning in the deilector and yet permit it to be readilywithdrawn from the latter in case it is desired t0 remove the deflector,the central portion of the shaft is preferably noncircular in crosssection andthe shaftreceiving vpassage through the deflector is the sameshape. The exposed end of the shaft is provided. With. a 1ere"r 34 forturning it in arder to swing the deector in a vertical plane,v and theleverl is locked-in adjusted positions by any suitable'means, such as atoothed segment 36 secured to the side of the riser and engaged by aretractible spring-pressed pin 31 connected to the lever in a well-knownmanner (Fig. 3).

To distribute coal uniformly over the fire-bed thelower surface of thedeilector in the path of coal thrown against it by the steam jets isprovided with a plurality of depending fuel-guiding ribs'. Preferablythere is a pair of forwardly and outwardly curved ribs 38 for directingcoal to the side portions of the grate near its rear end. By adjustingthe deector vertically by means of lever 34, and by adjusting steamjet'valves 29, any desired distribution of coal can be obtained.

It is a feature of this invention that substantially the same amount ofcoal is fed to the jet member on both sides of the riser screw.Accordingly, the normal conveyor thread 4l which extends upwardly fromthe lower en d of the riser screw terminates at a point a few inchesshort of the upper end of the screw hub 42 which is substantially in aplane pas-sing across the top of the jet member and the bottom of theclean-out door opening. The screw shown in the drawings is turned in aclockwise direction to raise the coal through the riser conduit, andconsequently thread 4I tends to push more coal toward the left of theriser outlet than toward the right. Some of the excess coal thusdeposited on the left side of the screw hub iscarried over to theopposite side of the hub by means of a reverse flight 43, that is, ascrew ight which extends around the hub in a direction opposite to thatof the -main thread. The reverse flight tends to push the .coalbackwardly against the main night, and between the opposing forces ofthese two nights coal is picked up, carried over the hub and depositedin the less dense coal on the opposite side of the hub to therebyequalize the amount of rcoal on both sides of the hub. The reverseilight is located in the coal up in the enlarged portion of the riserconduit ,sio that it will i not pack coal in the restricted lowerportionof the conduit. To prevent the reverse Hight from packing thecoal too tightly between it and the adjacent end of the main thread itextends only part way around the hub with its ends tapering into the hubas shown in Fig. 4, and its high point A is spaced from the oppositehigh point B` (the point in axial alignment therewith) of the mainthread a distance at least as great as the pitch of the latter. Also,the outer end of the reverse thread is disposed Ysubstantially opposite4the delivery end of the conveyor thread. With Y the reverse threadpositioned in this manner on the screw hub some of the .Coal istransferred from one side of the screw to the `other without packing inthe screw or in the conduit. As a further precaution against packing thereverse thread tapers in thickness away from the hub so that it will cut`through the coal like a knife.

According to the provisions of the patent statutes, I have explained theprinciple and mode of operation of my invention and have illustrated anddescribed what I now consider to represent its best embodiments.However, I desire to have it understood that, within the scope of theappended claims, thev invention may be practiced otherwise than asspecifically illustrated and described.

I claim:

1. A locomotive stoker riser conveyor screw for use in an inclined riserVconduit having an enlarged upper portion, said screw being .adapted toraise coal through the conduit to a jet member at its upper end, thescrew comprising a hub, a conveyor threadA encircling the Vhub for themajor portion. of its length and terminating short of its delivery end,and a reverse thread mounted I on the hub at its tip portion between itsdelivery end and the adjacent end of said conveyor thread, said reversethread being adapted to be disposed in the enlarged upper portion of theriser conduit part way around the hub, wherebyA the screw is adapted todeliver coal to the jet member substantially uniformly on both sides ofthe kscrew without harmful packing of the coal between said threads.

3. A locomotive Stoker conveyor screw forV use in an inclined riserconduit to raise coal therethrough to a jet member at the upper end ofthe conduit, said screw comprising a hub, a oonveyor thread encirclingthe hub for the major portion of its length and terminating short of itsdelivery end, and a reverse thread mounted on the hub between itsdelivery end and the adjacent end of said conveyor thread and extendingonly part way around the hub, at least haii of said reverse thread beingspaced from the opposing portion of said conveyor thread a distance atleast as great as the pitch of the conveyor thread, whereby the screw isadapted to deliver coal to the jet member substantially uniformly onboth sides of the screw without harmful packing of the coal between saidthreads.

4. A locomotive stoker conveyor screw for use in an inclined riserconduit to raise coal therethrough to a jet member at the upper end ofthe conduit, said screw comprising a hub, a conveyor thread encirclingthe hub for the major portion of its length, the delivery end portion ofsaid thread tapering into the hub at a point spaced from the adjacentend thereof, and a reverse thread extending only part way around the hubbetween its delivery end and the adjacent end of said conveyor threadwith its ends tapering into the hub, whereby the screw is adapted todeliver coal to the jet member substantially uniformly on both sides ofthe screw.

5. A locomotive stoker conveyor screw comprising a hub, a conveyorthread encircling the hub for the major portion of its length, thedelivery end portion of said thread tapering into the hub at a pointspaced from the adjacent end thereof, and a reverse thread extendingonly part way around the hub between its delivery end and the adjacentend of said conveyor thread with its ends tapering into the hub, thehigh point of the reverse thread being spaced from the opposite highpoint of the conveyor thread a distance at least as great as the pitchof the latter, and the outer end of said reverse thread being disposedsubstantially opposite the delivery end o1 said conveyor thread.

6. In a locomotive stoker, a riser conduit having an enlarged upperportion, a jet member connected to said upper portion, a screw rotatablymounted in the conduit and provided with a conveyor thread for raisingcoal through the conduit and delivering it to the jet member, said screwbeing adapted to be driven from its lower end and having a free upperend, said thread terminating short oi' the upper end of the screw, andsaid screw being provided at its tip portion in said enlarged portion ofthe conduit with a reverse flight between its upper end and the adjacentend oi the conveyor thread, said reverse flight being adapted to besubstantially completely buried in the coal in the conduit, whereby coalis delivered substantially uniformly to the jet member on both sides ofthe screw.

'7. In a locomotive stoker, a riser conduit having an enlarged upperportion, a jet member connected to said upper portion and having a topwall inclined downwardly from its center toward both sides of saidconduit, a screw rotatably mounted in the conduit and provided with aconveyor thread for raising coal through the conduit and delivering itto the jet member, said screw being adapted to be driven from its lowerend and having a free upper end, said thread terminating short of theupper end of thel screw, and said screw being provided at its tipportion in said enlarged portion of the conduit with a reverse ilightbetween its upper end and the adjacent end of the conveyor thread, saidreverse ight being adapted to be substantially completely buried in thecoal in the conduit, whereby coal is delivered substantially uniformlyto the jet member on both sides of the screw.

8. A locomotive stoker conveyor screw for use in an inclined riserconduit having an enlarged upper portion, said screw being adapted toraise coal through the conduit to a jet member at its upper end, thescrew comprising a hub, a conveyor thread encircling the hub for themajor portion of its length and terminating short of its delivery end,and a relatively short reverse thread mounted on the hub between itsdelivery end and the adjacent end of said conveyor thread, said reversethread being so positioned on said hub as to be restricted to theenlarged upper portion of the riser conduit, whereby the screw isadapted to deliver coal substantially uniformly on both sides of thescrew.

SAMUEL G. JONES.

